US Patent 7431075 Propellant fracturing of wells

A propellant assembly for fracturing a formation around a well includes a propellant and a detonating cord wrapped around the propellant, the detonating cord to ignite the propellant upon detonation of the detonating cord. Alternatively, the propellant can include a substantially central axial bore, with the propellant having a plurality of axial slots extending radially outwardly from the axial bore toward the outer surface of the propellant. A detonating cord is arranged within the axial bore of the propellant.